Silicidation is a common and frequently employed process in modern complementary metal oxide semiconductor (CMOS) manufacturing, e.g., to decrease contact resistance. Nickel silicide (NiSi) is often the material of choice for silicidation in nanometer scale technologies (e.g., with a critical dimension of 65 nm or less). However, the use of NiSi may introduce a variety of process complications and failure modes, e.g., increased or deleterious leakage, that can impact both the performance and yield of integrated circuits. Moreover, some silicidation defects may occur below a layer of silicon and are thus invisible to conventional optical inspection techniques.